Stabilizers ensuring a vertical position to two-wheeled vehicles

ABSTRACT

Stabilizing device for a two-wheeled vehicle, the device including two stabilizing wheels mounted, on either side of the bearing line of the wheels of the frame on the ground, on hydraulic supports which are connected to a jack for hydraulic adjustment of their length. A system of valves permits adjustment of the length of one of said stabilizing wheel supports independently of the length of the other support and of the action of the jack.

United States Patent Bobard et a1.

n51 3,693,987 [451 Sept. 26, 1972 [54] STABILIZERS ENSURING A VERTICALPOSITION TO TWO-WHEELED VEHICLES [72] Inventors: Emlle Bobard, P.O. Box17, Rue de Reon, Bcaunc, Cote d'Or; Just Delaunay, LEtang-Vergyi CotedOr, both ol France [22] Filed: May 24,1971

[21] Appl. No.: 146,077

[52] US. Cl. ..280/6 H, 280/124 F, 280/63 [51] Int. Cl. ..B60q 17/00[58] Field of Search ..280/63, 64, 65, 150 C, 6 H,

[56] References Cited UNITED STATES PATENTS 3,175,837 5/1972 Bobard..280/6.l

Primary Examiner-Philip Goodman Attorney-Roger Goudreau 7 1 ABSTRACTStabilizing device for a two-wheeled vehicle, the device including twostabilizing wheels mounted, on either side of the bearing line of thewheels of the frame on the ground, on hydraulic supports which areconnected to a jack for hydraulic adjustment of their length.

A system of valves permits adjustment of the length of one of saidstabilizing wheel supports independently of the length of the othersupport and of the action of the ack.

6 Claims, 7 Drawing Figures PATENTEDSEP26 1972 SHEET 2 [IF 2 Theinvention concerns a two-wheeled vehicle equipped with a stabilizingdevice capable of being controlled, at will, to ensure to the vehicle .aposition which may be vertical, perpendicular to the ground orintermediate between these two limit positions, whatever may be theslope of the ground over which this vehicle may travel..

Already known are vehicles having two wheels bearing a frame andequipped with a two-wheeled device arranged on either side of thebearing line of the wheels of the frame on the ground to ensure thestability of this frame in a direction perpendicular to the said bearingline.

Such devices comprise means for connecting stabilizing wheels to theframe, these means being associated to a jack connected to a circuit offluid under pressure in order to control, under the effect of thevariations of the load applied to the stabilizing wheels, displacementsin height of the latter wheels with a view to maintaining the vehicleperpendicular to the ground, whatever may be the slope of this ground. 7

The stabilization devices of the above type are often equipped, inaddition, with means symmetrically ensuring displacements which areequal in height and in opposite directions of the stabilizing wheels inorder to keep the vehicle on a practically vertical plane, whatever theslope of the ground over which the vehicle travels.

- The invention has for its object a vehicle having a frame carried bytwo wheels and equipped with a device of two'stabilizing wheels,arranged on either side 'of the bearing line of the wheels of the frameon the ground. Such a'stabilizing device comprises means of a hydraulicnature for connecting the stabilizing wheels to the frame, and ensures aposition of the vehicle which is perpendicular to the ground. A basicobject of the invention is to put forward means applicable to astabilization device of the above type, permitting, at will, whatevermay be the slope of of the ground, a position of the vehicle which maybe perpendicular to the ground, vertical or intermediate between thesetwo limit positions.

Another object of the invention is to propose simple means which may beeasily combined with the hydraulic means of a stabilization device of aknown type in order to ensure at will, whatever may be the slope of theground, a vertical position of the vehicle, or a position comprisedbetween the vertical position and the position perpendicular to theground.

Another object of the invention is to propose simple means, intended toequip the hydraulic means of a stabilization device of a known type, toensure automatically a vertical position of the vehicle, whatever may bethe slope of the ground. a

A further object of the invention is to put forward fluid distributionmeans applicable to a system of hydraulic chambers subjected to theaction of a jack of a stabilization device with a view to fluidtransfers causing displacements in height of one of the stabilizingwheels, these displacements ensuring, on sloping ground, vehiclepositions included between a position perpendicular to the ground and avertical position.

Other objects of the invention will become apparent in the followingdescription with respect to the accompanying drawings, which text anddrawings are given only by way of non-limitative example.

In the drawings,

FIGS. 1, 2 and 3 represent respectively side, transverse and plan viewsof a stabilizer of the invention;

FIG. 4 shows schematically, in section, the hydraulic circuits of thedevice of the invention;

FIGS. 5 and 6 show two special positions of the device of FIG. 4, toclarify the results obtained by the device, and

FIG. 7 is a schema relating to balance of a vehicle equipped with adevice of the invention.

In FIGS. 1 to 3, there is visible the silhouette of a tractor with twodrive steering wheels 1, 2 mounted in alignment below a raised frame 3.These wheels constitute a support base a, b which is too narrow toensure the balance of this tractor at ordinary speeds .of travel. Frame3 consequently has a fixed crossbar 4 with plunger arms 5d and 53, ateach end, which allow the mounting on either side of the tractor ofmechanisms with rods 6d, 6g and cranks 7d, 7g which comprise mechanismsfor association of two wheels 8d, 83 to frame 3, 5, the said wheelsbeing applied to the ground as will be explained below, thus to formwith wheels 1, 2 a quadrilateral of support, a, c, b, 11.

Each rod 6 comprises a piston rod 9 articulated on crank 7 and slidablein a cylinder 10 whose base is articulated in a bearing member 11 oncrossbar 4, so that rod 6 constitutes a prop of adjustable length forits wheel 8.

Props 6 can be controlled by a hydraulic device 12 which comprisessubstantially (FIG. 4) a system of three jacks 16a, 17a, 18a. Thissystem of jacks 16a to 18a includes a cylinder 13a with two coaxialrecesses for two pistons 14a, 15a which are rigidly connected, so thatin their respective recesses there are a jack 16a, an annular jack 17aand a jack 18a with jacks 16a opposed to the action of jacks 17a and18a.

Thus, it can be seen that jack 16a is able to counterbalance at leastone of the expansions of two other jacks 17a and 18a.

In addition, jack 16a presents a conduit which takes off from the drivecircuit of a pump 19, upstream of two identical valves 20d, 20g disposedin series in said circuit.

Each valve presents a slide with annular flow constriction element 21and a piston 22 which is urged toward a position of closure by a spring23. Said valve can be opened by the action of the fluid from jack 17a(or and cylinder 10, to which said valve is connected.

The operation of this device is described in copending application Ser.No. 819,199 filed Apr. 25, 1969 now U.S. Pat. No. 3,610,646 and isrepeated below for clearer understanding of the device of the invention.

The pump 19 permanently sucks the fluid from tank l9n and passes thisfluid toward valves 20d, 203. This fluid passes through the constrictionelements 21 of these valves without causing an action capable ofmodifying the position of their slides, then returns to the tank 19n,establishing a circuit whereof tank l9n constitutes a part that issubject to atmospheric pressure.

The slide of each valve 20 is thus subjected only to two thrusts ofopposed direction: the thrust of the spring 23 and the thrust of thefluid on the piston 22. These thrusts (to which reference will again bemade hereinbelow) have the effect of moving the constriction element 21inside the cylinder in order to regulate the flow section of the circuitof pump 19.

The regulation of the flow section of this circuit ensures, bythrottling of the stream, regulation of the pressure of the fluid of thepart of the circuit situated upstream of valves 20d, 20g and, inparticular, the pressure of the fluid of the jack 16a.

The force applied by this pressure of the fluid on the piston 14a ofjack 16a counterbalances the forces applied on pistons 15a, 140' by thepressures of the fluids of the jacks 17a, 18a.

The chambers of these two jacks 17a, 18a are connected to the respectivecylinders g, 10d to apply on wheels 8, by means of props 6, forcesensuring the stability of the vehicle in the crosswise direction c,d

The load F of the tractor is in fact balanced (on a horizontal orinclined terrain) by the reactions fa, jb of wheels 1 and 2 and by oneat least of the two reactions fc,fd of wheels 8d, 8g of the device (FIG.7).

To these reactions fc, fd correspond thrusts kc, kd of the respectiveprops 6d, 6g on the wheels 8 and these thrusts kc, kd determine, in theclosed volume systems 17a-10 and l8a-l0d, pressures which aretransmitted to the chambers with pistons 22 of the respective valves20d, 20g.

In this way, the thrust applied by the fluid on a piston 22 (whichthrust is a function of the section of this pistonand of said pressure)counterbalances the thrust of the spring 23 (which is a function of thecrushing of said spring) in order to ensure to its construction element21 a position of balance which is consequently a function of thecorresponding load kc (or kd).

In the case of a crosswise inclined position of the tractor on flatterrain, thrusts kc, kd and consequently the pressures. of the hydraulicsystems (such as 17a-10g are different from each other; the valve 20connected to the hydraulic system of the wheel 8 bearing the smallerload (for example wheel 8d in the case of FIG. 7) is in a more closedposition than the other valve, so that the element 21 of this valvetakes up a position which ensures to the jack 16a a pressure sufficientfor the force of the piston 14 to be equal to the arithmetical sum ofthe forces of the pistons 14a, 15a which correspond to thrusts kc, kd ofwheels 8d and 8g.v

Since the closed volume systems 17a-10g, 18a-10d are identical to eachother, the action of the jack 16a, in the direction of its expansion,obviously causes equal elongation of props 6d, 6g so that, in all cases,the median plane of the tractor has a normal position along the bearingline of wheels 8d, 8g.

Obviously, the power of the pump 19 is appropriate for the maximumpressure to be developed in jack l6 and the crush-resistance of theclosing spring is appropriate for a gradual valve-opening action.

As a result, taking into account the loads which may be applied towheels 8 and the corresponding forces of jacks 16a, 17a and 18a, thereare chosen, preferably for the particularities of a valve 20, valueswhich ensure, in the case of a tractor on horizontal ground, thrusts onwheels 8 sufficiently great to maintain the tractor in a perpendicularposition which corresponds substantially to its position of unstablebalance but low enough not to modify appreciably the loads applied towheels 1 and 2 for good sticking of said wheels on the ground.

It is possible to obtain righting effects for the vehicle by using aremarkably simple device which allows transfer of fluid from the rodcylinders to jacks associated with said cylinders.

Thanks to such a device (FIG. 4), the capacity of jacks 17a and 18a withvalves 20 allows extensions and shortenings of corresponding rods 6which are appropriate for the maximum angle of righting of the vehicle,taking into account the transverse angle which elastic tires can assumewithout skidding (FIGS. 5 and 6). Besides, the connecting conduit, forexample for cylinder 10d and jack 18a, presents a two-branch element 41connected to middle port 42 of a distributor 43 which has two otherports 44a and 44b, respectively connected to a source of fluid underpressure and to a discharge circuit which is not pressurized, to whichreference will be made later.

Distributor 43 presents a slide, with median groove 45 which can becontrolled manually by a lever 46 or automatically controlled by thedifferences of pressure applied to the end faces of two pistons 47a, 47bwhich are separated by the groove 45 to ensure closing of ports 44a, 44b(FIG. 4) and communication of port 42 and port 44a (FIG. 6) or port 44b(FIG. 5). In this way the ends of distributor 43, being connected tocylinders 10, and the slide being subject to an antagonistic urging oftwo recall springs (not referenced), when there is a variation of groundslope (FIG. 5), wheel 8g tends to be overloaded as compared with wheel8d, and the dis tributor slide 43 ensures communication of conduit 41and exhaust 44b, which allows the following sequence of operations: atleast partial emptying of cylinder 10d, to shorten rod 6dwhich is at theupper lever, closing valve 20d by a drop of pressure on said rod tosupply jack 16a and consequently partly empty jack 18a via distributor43 and discharge 44b driving the fluid of jack 17a into cylinder 10g toelongate rod 6g.

Obviously, the tractor is positioned substantially vertically withoutlifting its wheels 1, 2 because of shifts in opposite directions ofwheels 8 with respect to the frame; these shifts are appropriate to theslope and contour of the terrain.

An identical result may be obtained by a slightly different process whenwheel 8g is the lower one (FIG. 6). For this position, because of thereduction of the load on cylinder 10d, the slide establishescommunication between port 44a of the pressurized fluid circuit andbranch 41 to supply cylinder 10d and jack 18a, which has the effect ofopening valve 20d.

In any case, the supply must be sufficient to tend to lift the tractorin such a way that the pressure in cylinder 10g, through it is less thanthat of cylinder 10d, will ensure communication 44a, 41 adequate foropening valve 20g and consequently effecting the transfer of fluid fromcylinder 10g into jack 17a, retracting pistons 14a and 15a and effectinga flow of fluid from pump 19 and jack 16a via the unpressurized circuitback to tank l9n.

The two jacks 16a and 18a alternately play the role of supporting jack,and although valves 20 play a role identical with that described above,the asymmetry of operation of cylinders d, 10g is due to the fact that-one of them, namely 10g, is connected to one of the auxiliary jacks(17a) to constitute a closed constantvolume system, whereas the othercylinder (10d) can be connected by the slide to the circuits of a systemwhich allow either escape of the fluid or supply of pressurized fluid.

Such a supply could be ensured by a pump like pump 19, but to avoidutilization of second pump, pump 19 is supplied with a known means whichpermits division of its flow into two streams, one of which, connectedto jack 16a, presents a constant output, the circuit of the other flowbeing connected to port 44a of distributor 43.

It is obvious that various changes and modifications may be made to thedetails of construction without thereby departing from the generalspirit of the invention as set forth in the appended claims.

What is claimed is: l. A vehicle having: a. a frame (3, 4,5), b. wheels(1, 2) supporting the frame in an unstable manner in one direction (0,d) perpendicular to the general direction (a, b) of the points wheresaid wheels (1,2) touch the ground, c. a stabilizing device for thedirection of instability (c, d) comprising: two elements for bearing onthe ground (8d, 8g placed on either side of the bearing line (a, b) ofthe wheels (1, 2) and spaced from the latter,

means (6d, 10d; 6g, 103) for connecting said bearing elements to theframe, comprising cylinders with pistons forminghydraulic chambers (10d,10g) permitting displacements in height of said bearing elements,

an assembly of two hydraulic chambers (17a, 18a) connected respectivelyto said hydraulic chambers of the connection means (10d, 10g) and a jack(16a) capable of ensuring a return of fluid from said hydraulic chambers17a, 18a) towards the chambers of the bearing elements,

a fluid circuit comprising a connection to said jack (16a) and means(20d, 20g) placed downstream of said connection in order to regulate thepressure in the upstream portion of the circuit, as a function of thevariations of pressure of the hydraulic chambers (10d, 10g) of theconnection means,

fluid distribution means (43) connected to one of the chambers (18a), tothe downstream part (l9n) of said circuit and to a second circuit(44-19) equipped with supply means of a fluid under pressure.

2. A vehicle according to claim 1, wherein the means for supplying thesecond fluid circuit comprises a flow divider mounted on the fluidcircuit, upstream of the connection to the jack (16a) of the device.

3. A vehicle according to claim 1, wherein the fluid distribution meanscomprises a cylinder having a slidevalve (45) provided to be controlledunder the effect of a pressure difference in the chambers (10d, 10g) ofthe connection means of the bearing elements.

4. A vehicle according to claim 1, wherein the fluid distribution meanscomprises a cylinder having a slidele'd'thaaltle 46. SY A iI lEiEl e tcor d in g to g rh 4f w r ein the slidevalve cylinder of thedistribution means comprises a connection to the jack (16a) of thestabilizing device.

6. A vehicle according to claim 4, wherein the slidevalve cylinder ofthe distribution means comprises another connection to the downstreampart of the first fluid circuit.

1. A vehicle having: a. a frame (3, 4, 5), b. wheels (1, 2) supportingthe frame in an unstable manner in one direction (c, d) perpendicular tothe general direction (a, b) of the points where said wheels (1, 2)touch the ground, c. a stabilizing device for the direction ofinstability (c, d) comprising: two elements for bearing on the ground(8d, 8g ) placed on either side of the bearing line (a, b) of the wheels(1, 2) and spaced from the latter, means (6d, 10d; 6g, 10g) forconnecting said bearing elements to the frame, comprising cylinders withpistons forming hydraulic chambers (10d, 10g) permitting displacementsin height of said bearing elements, an assembly of two hydraulicchambers (17a, 18a) connected respectively to said hydraulic chambers ofthe connection means (10d, 10g) and a jack (16a) capable of ensuring areturn of fluid from said hydraulic chambers (17a, 18a) towards thechambers of the bearing elements, a fluid circuit comprising aconnection to said jack (16a) and means (20d, 20g) placed downstream ofsaid connection in order to regulate the pressure in the upstreamportion of the circuit, as a function of the variations of pressure ofthe hydraulic chambers (10d, 10g) of the connection means, fluiddistribution means (43) connected to one of the chambers (18a), to thedownstream part (19n) of said circuit and to a second circuit (44-19)equipped with supply means of a fluid under pressure.
 2. A vehicleaccording to claim 1, wherein the means for supplying the second fluidcircuit comprises a flow divider mounted on the fluid circuit, upstreamof the connection to the jack (16a) of the device.
 3. A vehicleaccording to claim 1, wherein the fluid distribution means comprises acylinder having a slide-valve (45) provided to be controlled under theeffect of a pressure difference in the chambers (10d, 10g) of theconnection means of the bearing elements.
 4. A vehicle according toclaim 1, wherein the fluid distribution means comprises a cylinderhaving a slide-valve equipped with manual control means (46).
 5. Avehicle according to claim 4, wherein the slide-valve cylinder of thedistribution means comprises a connection to the jack (16a) of thestabilizing device.
 6. A vehicle according to claim 4, wherein theslide-valve cylinder of the distribution means comprises anotherconnection to the downstream part of the first fluid circuit.